1. A core consists of 157 fuel assemblies, each fuel assembly forming a square-lattice

17x17 array. In each assembly, 24 locations of that lattice are reserved for control

assembly rodlets, and additionally, the central location is reserved for instrumentation.

The remaining locations contain fuel rods. Fuel rods are formed by UO2 fuel pellets clad

in Zr-based cladding. The outside cladding diameter is 0.374", the clad thickness is

0.0225", and the diametral gap is 0.0065". (This is the gap between the clad and pellet;

note that the diametral gap is twice the radial gap.) Axially, the fuel pellet stack (so-called

active core) is 14 feet tall. Pellets are made of UO2 sintered to 95.5% of its theoretical

density which is 10.96 g/cm3. Dishing and chamfering amount to 1% of the pellet

volume. Assume that fuel enrichment is 4 wt%. The thermal power of AP 1000 is 3,400

MW-th.

a. Calculate the total heavy metal loading, i.e., the total uranium weight in the cycle

1 fresh core. [Justify all assumptions.]

b. Calculate specific power expressed in W/gU. Also, calculate specific power

expressed in MW/tU.

c. Assume that the reactor has an annual refueling cycle composed of 15 days of

shutdown for refueling, and the remaining -11.5 months of operation at power.

Further assume that the average capacity factor, when operating at power, is

98%. What is the average burnup that fuel receives each year? You may express

burnup in MWd/tU or GWd/tU or MWd/kgU. [Note that "t" will always denote

metric tons, i.e., 1,000 kg, unless very specifically stated otherwise. Also, U in

burnup units refers to the initial mass of uranium (ALL uranium, not just U235).